Proceedings of the 2. VDI Fachkonferenz Humanoide Roboter. VDI Fachkonferenz Humanoide Roboter December 5-6 München Germany VDI Fachkonferenz Humanoide Roboter 12/2017.
his article provides an overview of the humanoid robot RH5 developed at the DFKI Robotics Innovation Center. The robot, with a total size of 200 cm and a weight of 62 kg, has an almost humanoid dimension. A total of 34 degrees of freedom were provided, of which 12 DOF are related to the legs, 3 each to a torso and neck kinematics as well as 16 DOF to the arms and grippers of the robot. From the experience in the development of complex robotic systems at the DFKI, special attention was paid to the multi-modal sensor equipment and the hardware present in the system during the development of the system. In the course of the developments in the area of embedded hardware, it can be stated, that a distributed computer architecture contributes both to increasing the robustness as well as to the relief of central data processing units. With the increasing computing power and the increasing convergence of classical microcontrollers and standard computers, the processing of sensor data can now be transferred from low-level and high-level processing to first- and second-level processing, since complex algorithms already take place in the early stages of the processing chain. As a result, local processing loops are possible, which already allow subsystems of robots to be operated with a high degree of autonomy. A special focus was placed on the mechanical development of the bipedal platform. The humanoid robot can thus, e.g. to perform manipulation tasks, both stand statically stable and walk dynamically at a speed of up to 1 m / s. Therefor a lightweight and stiff structure was achieved by optimizing the topology. The mechanical boundary conditions necessary for the dimensioning were determined beforehand by multibody simulations. In order to improve the dynamic behavior during walking, the mass center of the legs was designed as close as possible to the rotation axes of the hip joints. By the use of linear drives especially developed
for this robot the mass distribution in the legs could be promoted. On the other hand, the non-constant ratio caused by variation of the effective lever length between the joint and the attack point of the actuator was positively used. By suitable alignment of the force-acting points of the actuators, suitable gear ratios could be found depending on the joint angle. In the linear drives used in the forward direction (pitch direction) of the leg joints, an optional possibility was provided for the use of manually adjustable serial elasticities. As a result, it will be possible to stepwise implement elastic walking behavior.